Carbonaceous cement



h 1954 c. E. GREIDER ETAL CARBONACEOUS' CEMENT Filed Oct. 27, 1952 Cement INVENTORS CLARENCE E. GREIDER MYRON R.NULL

Patented Oct. 19, 1954 CARBONAOEOUS CEMENT Clarence E. Greider, Lakewood, and Myron R. Null, Berea, Ohio, assignors to Union Carbide and Carbon Corporation, a corporation of New York Application October 27, 1952, Serial No. 317,094

3 Claims.

This invention relates to a carbonaceous cement particularly suited for use in joining illuminating carbons.

Recent developments in arc lamps for motion picture projection, searchlights, and the like have increased the consumption rate of the positive electrode to such an extent that the time of continuous operation is substantially reduced. At the same time there is a growing demand for longer periods of continuous operation of such devices. Due to the construction of lamps and electrode feeding devices it is impractical to lengthen the positive electrodes suificiently to provide the desired increased life. Accordingly, there is a demand for some means of connecting a new electrode to a partially consumed electrode to provide continuous operation.

It is the principal object of this invention to satisfy this demand, and another important object of the invention is a carbonaceous cement, particularly suited for use in joining illuminating carbon electrodes.

In the drawing, Fig. 1 is an elevational view of portions of electrodes to be joined in accordance with the invention; and

Fig. 2 is a view similar to Fig. 1 but partially in section showing a typical electrode joint embodying the invention.

The invention comprises a carbonaceous cement consisting of finely-divided carbon, an aqueous sugar solution as a binder, and an amine selected from the group consisting of monoethanolamine, diethanolamine and triethanolamine. More specifically the cement contains about 45 to 55 parts by weight each of carbon and binder and 5 to 15 parts by weight of amine. A preferred binder is a solution containing about 75 parts by weight of glucose and 25 parts by weight of water. A typical cement embodying the invention contains, by weight, 48 parts carbon flour, 52 parts binder and parts monoethanolamine.

The invention also comprises a sectional positive illuminating carbon electrode, the individual sections of which are joined and bonded together by the cement of the invention. Referring to the drawing, a sectional electrode illustrative of the invention may comprise an electrode section 10 having a conventional core ll of rare earths. A recess [2 is provided at one end of the electrode section It. A similar electrode section 13 is provided with a tongue M adapted to fit into the recess I2. In accordance with the invention, the electrode sections Ill, I3 are bonded together by a layer I5 of the cement of the invention with the tongue l4 inserted in the recess l2.

In using the cement of the invention for joining electrode sections, it is applied either to the recess of one section or the tongue of another section, or to both, and is allowed to dry. As a section is consumed during use in an arc lamp, another section may be added to it by inserting its tongue into the recess of the section already in use. As the joint approaches the jaws holding the electrode, the heat from the arc conducted through the carbon causes the binder of the cement to coke (i. e. to become carbonized) and in coking to bond the two sections together.

To be useful for joining electrode sections as described a cement must retain sufficient plasticity after it is applied to permit a good fit and must provide a strong bond so that the sections do not separate as the electrode is consumed in the arc. The amine included in the cement of the invention is essential to the attainment of both of these characteristics.

What is claimed is:

1. A carbonaceous cement consisting of about 45 to parts by weight of finely-divided carbon; 45 to 55 parts by weight of an aqueous sugar solution as a binder; and 5 to 15 parts by weight of at least one compound selected from the group consisting of monoethanolamine, diethanolamine, and triethanolamine.

2. A carbonaceous cement consisting of about 45 to 55 parts by weight of finely-divided carbon; 45 to 55 parts by weight of an aqueous solution of glucose as a binder; and 5 to 15 parts by weight of at least one compound selected from the group consisting of monoethanolamine, diethanolamine, and triethanolamine.

3. A carbonaceous cement consisting of about 45 to 55 parts by weight of finely-divided carbon; 45 to 55 parts by weight of an aqueous solution of glucose as a binder; and 5 to 15 parts by weight of monoethanolamine.

Name Date Beckwith Dec. 25, 1883 Number 

1. A CARBONACEOUS CEMENT CONSISTING OF ABOUT 45 TO 55 PARTS BY WEIGHT OF FINELY-DIVIDED CARBON; 45 TO 55 PARTS BY WEIGHT OF AN AQUEOUS SUGAR SOLUTION AS A BINDER; AND 5 TO 15 PARTS BY WEIGHT OF AT LEAST ONE COMPOUND SELECTED FROM THE GROUP CONSISTING OF MONOETHANOLAMINE, DIETHANOLAMINE, AND TRIETHANOLAMINE. 